In previously known training bicycles, which in more modern versions frequently are used for so called spinning, the two pedal devices are oriented in 180° to each other and rigidly united to a mutual shaft to which a chain wheel for one single transmission in the form of an endless chain is rigidly united, which transmits the driving power to the wheel, which power the exercising person applies to the pedals via his/her legs. In practice, this construction gives a mediocre and partly monotonous training of the body. Thus, energy demanding power transmission from the legs of the user to each individual pedal device takes place in the main only the half revolution during which the pedal device is brought to move in the direction forwards from the area of an upper dead centre to the area of a lower dead centre. During the return movement backwards from the lower dead centre towards the upper dead centre, the individual leg is, however, kept in all essentials in a position of rest so far that the same inactively accompanies the pedal in question when the other leg depresses the opposite pedal. This pattern of movement results in a low physiological degree of efficiency, inasmuch as the individual leg's own weight (which frequently is within the range of 15-25 kg) contributes to apply the individual pedal force during the single movement which requires marked energy consumption, viz. the depression, as well as inasmuch as only certain muscle groups in, above all, the exercising person's legs, back and stomach need to be activated during the movement of depression, viz. the muscles which can apply the pedal compressive force.